<!DOCTYPE html>
<html lang="en">
	<head>
		<title>three.js webgl - lines - spheres</title>
		<meta charset="utf-8">
		<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
		<link type="text/css" rel="stylesheet" href="main.css">
	</head>
	<body>

		<div id="info">
			<a href="https://threejs.org" target="_blank" rel="noopener">three.js</a> - lines WebGL demo
		</div>

		<script type="module">

			import * as THREE from '../build/three.module.js';

			const SCREEN_WIDTH = window.innerWidth,
				SCREEN_HEIGHT = window.innerHeight,

				r = 450;

			let mouseY = 0,

				windowHalfY = window.innerHeight / 2,

				camera, scene, renderer;

			init();
			animate();

			function init() {

				camera = new THREE.PerspectiveCamera( 80, SCREEN_WIDTH / SCREEN_HEIGHT, 1, 3000 );
				camera.position.z = 1000;

				scene = new THREE.Scene();

				const parameters = [[ 0.25, 0xff7700, 1 ], [ 0.5, 0xff9900, 1 ], [ 0.75, 0xffaa00, 0.75 ], [ 1, 0xffaa00, 0.5 ], [ 1.25, 0x000833, 0.8 ],
					[ 3.0, 0xaaaaaa, 0.75 ], [ 3.5, 0xffffff, 0.5 ], [ 4.5, 0xffffff, 0.25 ], [ 5.5, 0xffffff, 0.125 ]];

				const geometry = createGeometry();

				for ( let i = 0; i < parameters.length; ++ i ) {

					const p = parameters[ i ];

					const material = new THREE.LineBasicMaterial( { color: p[ 1 ], opacity: p[ 2 ] } );

					const line = new THREE.LineSegments( geometry, material );
					line.scale.x = line.scale.y = line.scale.z = p[ 0 ];
					line.userData.originalScale = p[ 0 ];
					line.rotation.y = Math.random() * Math.PI;
					line.updateMatrix();
					scene.add( line );

				}

				renderer = new THREE.WebGLRenderer( { antialias: true } );
				renderer.setPixelRatio( window.devicePixelRatio );
				renderer.setSize( SCREEN_WIDTH, SCREEN_HEIGHT );
				document.body.appendChild( renderer.domElement );

				document.body.style.touchAction = 'none';
				document.body.addEventListener( 'pointermove', onPointerMove );

				//

				window.addEventListener( 'resize', onWindowResize );

				// test geometry swapability

				setInterval( function () {

					const geometry = createGeometry();

					scene.traverse( function ( object ) {

						if ( object.isLine ) {

							object.geometry.dispose();
							object.geometry = geometry;

						}

					} );

				}, 1000 );

			}

			function createGeometry() {

				const geometry = new THREE.BufferGeometry();
				const vertices = [];

				const vertex = new THREE.Vector3();

				for ( let i = 0; i < 1500; i ++ ) {

					vertex.x = Math.random() * 2 - 1;
					vertex.y = Math.random() * 2 - 1;
					vertex.z = Math.random() * 2 - 1;
					vertex.normalize();
					vertex.multiplyScalar( r );

					vertices.push( vertex.x, vertex.y, vertex.z );

					vertex.multiplyScalar( Math.random() * 0.09 + 1 );

					vertices.push( vertex.x, vertex.y, vertex.z );

				}

				geometry.setAttribute( 'position', new THREE.Float32BufferAttribute( vertices, 3 ) );

				return geometry;

			}

			function onWindowResize() {

				windowHalfY = window.innerHeight / 2;

				camera.aspect = window.innerWidth / window.innerHeight;
				camera.updateProjectionMatrix();

				renderer.setSize( window.innerWidth, window.innerHeight );

			}

			function onPointerMove( event ) {

				if ( event.isPrimary === false ) return;

				mouseY = event.clientY - windowHalfY;

			}

			//

			function animate() {

				requestAnimationFrame( animate );

				render();

			}

			function render() {

				camera.position.y += ( - mouseY + 200 - camera.position.y ) * .05;
				camera.lookAt( scene.position );

				renderer.render( scene, camera );

				const time = Date.now() * 0.0001;

				for ( let i = 0; i < scene.children.length; i ++ ) {

					const object = scene.children[ i ];

					if ( object.isLine ) {

						object.rotation.y = time * ( i < 4 ? ( i + 1 ) : - ( i + 1 ) );

						if ( i < 5 ) {

							const scale = object.userData.originalScale * ( i / 5 + 1 ) * ( 1 + 0.5 * Math.sin( 7 * time ) );

							object.scale.x = object.scale.y = object.scale.z = scale;

						}

					}

				}

			}


		</script>
	</body>
</html>
